In the 3rd Generation Partnership Project (3GPP), a radio access method and a radio network for cellular mobile communications (hereinafter, referred to as “Long Term Evolution (LTE)”, or “Evolved Universal Terrestrial Radio Access (EUTRA)”) have been considered (NPL 1, NPL 2, NPL 3, NPL 4, and NPL 5). In LTE, a base station device is also referred to as an evolved NodeB (eNodeB), and a terminal device is also referred to as User Equipment (UE) or a mobile station device. LTE is a cellular communication system in which an area is divided into multiple cells to form a cellular pattern, each of the cells being served by a base station device. A single base station device may manage multiple cells.
LTE supports a Time Division Duplex (TDD). LTE that employs a TDD scheme is also referred to as TD-LTE or LTE TDD. In TDD, an uplink signal and a downlink signal are time-division multiplexed. LTE supports a Frequency Division Duplex (FDD).
In 3GPP, Carrier Aggregation (CA) has been specified in which a terminal device can simultaneously perform transmission and/or reception on up to five serving cells (component carriers: CC).
In 3GPP, a configuration where a terminal device simultaneously performs transmission and/or reception on more than five serving cells (component carriers) has been considered. Furthermore, a configuration where a terminal device performs transmission on a Physical Uplink Control CHannel (PUCCH) in a secondary cell that is a serving cell other than a primary cell has been considered (NPL 6).
In 3GPP, a configuration where a new format for the PUCCH and/or a Physical Uplink Shared CHannel (PUSCH) is used to simultaneously transmit Channel State Information (CSI) of multiple serving cells has been considered.